In:
Biochemical Journal, Portland Press Ltd., Vol. 331, No. 1 ( 1998-04-01), p. 283-289
Abstract:
Although the oxytocin receptor modulates intracellular Ca2+ ion levels in myometrium, the identities of signal molecules have not been clearly clarified. Our previous studies on oxytocin receptor signalling demonstrated that 80 kDa Ghα is a signal mediator [Baek, Kwon, Lee, Kim, Muralidhar and Im (1996) Biochem. J. 315, 739–744]. To elucidate the effector in the oxytocin receptor signalling pathway, we evaluated the oxytocin-mediated activation of phospholipase C (PLC) by using solubilized membranes from human myometrium and a three-component preparation containing the oxytocin receptor–Ghα–PLC-δ1 complex. PLC-δ1 activity in the three-component preparation, as well as PLC activity in solubilized membranes, was increased by oxytocin in the presence of Ca2+ and activated Ghα (GTP-bound Ghα). Furthermore the stimulated PLC-δ1 activity resulting from activation of Ghα via the oxytocin receptor was significantly attenuated by the selective oxytocin antagonist desGly-NH2d(CH2)5[Tyr(Me)2,Thr4] ornithine vasotocin or GDP. Consistent with these observations, co-immunoprecipitation and co-immunoadsorption of PLC-δ1 in the three-component preparation by anti-Gh7α antibody resulted in the PLC-δ1 being tightly coupled to activated Ghα on stimulation of the oxytocin receptor. These results indicate that PLC-δ1 is the effector for Ghα-mediated oxytocin receptor signalling.
Type of Medium:
Online Resource
ISSN:
0264-6021
,
1470-8728
Language:
English
Publisher:
Portland Press Ltd.
Publication Date:
1998
detail.hit.zdb_id:
1473095-9
SSG:
12
Permalink